A rotary electric machine has a stator and a rotor. The rotor is formed in a substantially cylindrical shape and rotatably provided relative to the stator.
In most rotary electric machines, a stator is configured so as to oppose an outer circumferential surface of a rotor, and the rotor includes magnets magnetized in a radial direction. Further, the stator generates magnetic flux along the radial direction of the rotor and exerts the magnetic fields which effect the magnets of the rotor. Thus, in most such rotary electric machines, the rotor is rotated as a result of the stator-rotor magnetic interaction in the radial direction of the rotor.
On the other hand, a rotary electric machine comprising stators installed on the end face components of a rotor along a rotating axis direction has been known (JP 10-271784 Å). In this type of rotary electric machine, the rotor includes magnets magnetized in the rotating axis direction. In addition, the stators generate magnetic flux along the rotating axis direction of the rotor and exerts magnetic fields on the magnets of the rotor. In the rotary electric machine having the stators installed on the components of the end faces of the rotor in the rotating axis direction as described above, the rotor is rotated by the stator-rotor magnetic interaction in the rotating axis direction of the rotor.
Accordingly, in order to manufacture a rotary electric machine capable of outputting high torque, it is necessary that stators, in addition to being mounted on the circumferential surface of a rotor, be mounted on both end faces of the rotor in a rotating axis direction, such that the rotor can thus be rotated by means of the stator-rotor magnetic interaction occurring in both the radial direction and the rotating axis direction of the rotor.
However, because the stators mounted on the end faces of the rotor in the rotating axis direction are placed along the radial direction of the rotor and include a core whose inner circumference is narrower than its outer circumference, the stators suffer from a problem that magnetic saturation is more likely to occur in such stators than in a stator placed opposing to a circumferential surface of the rotor. As a result, torque problematically declines in a high power range.
The present invention, which addresses the above-described problems, advantageously provides a rotary electric machine capable of making effective use of both end faces of a rotor in a rotating axis direction while suppressing magnetic saturation.